Weather

441 
fxus63 ktop 071749 
afdtop 


Area forecast discussion 
National Weather Service Topeka Kansas 
1249 PM CDT sun Sep 7 2008 


Update... 


Updated for 18 UTC aviation. 


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Discussion... 


See previous discussion. 




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Aviation... 


Scattered-broken MVFR ceilings will be possible through the 21z period near a 
weak boundary near Interstate 70...then expect VFR clouds and visibilities 
until later this evening when convection is expected to develop 
after 07z. Will continue trend of adding cumulonimbus to tafs for now with 
MVFR ceilings forming again toward 11z. Model soundings suggest ifrcigs 
possible after 15z and will only add some scattered clouds near 007 for 
now. Precipitation will be scattered through 18z Monday. 


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Previous discussion... /issued 743 am CDT sun Sep 7 2008/ 


Discussion... 


Updated the forecast to remove mention of dense fog from the north 
central Kansas zones and cancelled the dense fog advisory. It 
appears that middle level clouds moving into the area and some 
scattered to isolated rain shower activity has helped diminish the 
intensity of the fog across north central Kansas this morning. 
Additionally high pressure center seems to be moving east of north 
central Kansas allowing at least some weak surface winds to aid in mixing 
out dense fog this morning. The rest of the forecast package 
remained in good shape...so no additional changes necessary. 


Cavanaugh 


Previous discussion... /issued 243 am CDT sun Sep 7 2008/ 


Discussion... 


Stratus and fog over most of the County Warning Area at this time...with dense fog in northwest 
counties where better clearing occurred. Showers and ts moving 
across SC Kansas along frontal boundary...with surface temperatures falling into 
the 50s. 


For today and tonight...will pull fog at 15z from NE 
counties...and keep slg chance of rain showers this morning along 
i70 and points southward. By later this afternoon...developing 
southerly flow in the middle levels aids in return of instability and 
convergence over our area...and have added some thunder to far 
southern zones in the afternoon. From 0-12z...low level jet 
strengthens and tightens the 850mb front right over our 
area...then lifts it quickly northward around 12z. 
Meanwhile...next wave moves into the state across this 
boundary...enhancing storm development. GFS is a bit more 
aggressive moving the boundary northward while NAM keeps it over 
our northern County Warning Area. Have increased probability of precipitation to the north after 
midnight...and may get some strong to severe storms elevated over 
the boundary toward morning. Incoming upper wave then brings the 
front quickly southward through the day Monday. Wave moves from 
west to east across our state....rather than a sharp drop to the 
south. This keeps best energy to our north...but with instability 
built up along and south of the front...slight chance for a severe 
storm over our area remains. Have breezy conditions as the front 
comes through. High temperature grids could be a little warm for 
sun/Monday depending on amount of cloud cover today and speed of the 
frontal passage on Monday. 


Monday night through Wednesday...precipitation to clear NE Kansas through the 
overnight hours Tuesday and have drawn probability of precipitation as such...becoming dry 
across the entire area after midnight. This brings a clearer cool 
day with highs in the lower 70s as area remains under the 
influence of cool high pressure. High moves eastward through the 
day Wednesday...and front which has pushed southward then retreats 
back eastward and washes out as it does so. This brings warmer 
southerly flow for Wednesday and may make it back into the 80s 
this day. Have kept a slt chance pop considering retreating 
boundary. No changes beyond Wednesday. 67 


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Top watches/warnings/advisories...none. 


&& 


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